Merge pull request #44 from drowe67/dr-datac14

datac14 - FreeDATA Feature Request 002 for a < 1s, 5 byte signalling mode

24 files changed, 721 insertions, 16 deletions

diff --git a/CMakeLists.txt b/CMakeLists.txt
index ff1b295..aa518d8 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -662,6 +662,13 @@ endif()
                             cd ${CMAKE_CURRENT_BINARY_DIR}/src;
                             cat test.raw | ./ofdm_demod --mode datac13 --out /dev/null --testframes --ldpc --verbose 2 --packetsperburst 1")
              
+    # DATAC14 Octave Tx, C Rx, burst mode
+    add_test(NAME test_OFDM_modem_datac14_octave
+             COMMAND sh -c "cd ${CMAKE_CURRENT_SOURCE_DIR}/octave;
+                            DISPLAY=\"\" octave-cli -qf --eval 'ofdm_ldpc_tx(\"${CMAKE_CURRENT_BINARY_DIR}/src/test.raw\",\"datac14\",1,3,\"awgn\",\"bursts\",5)';
+                            cd ${CMAKE_CURRENT_BINARY_DIR}/src;
+                            cat test.raw | ./ofdm_demod --mode datac14 --out /dev/null --testframes --ldpc --verbose 2 --packetsperburst 1")
+             
     # DATAC4 C Tx, C Rx, burst mode
     add_test(NAME test_OFDM_modem_datac4_ldpc_burst
              COMMAND sh -c "cd ${CMAKE_CURRENT_BINARY_DIR}/src;
@@ -676,7 +683,14 @@ endif()
                             ./ch - - --No -17 |
                             ./ofdm_demod --mode datac13 --out /dev/null --testframes --ldpc --verbose 2 --packetsperburst 1")
 
-   # -------------------------------------------------------------------------
+    # DATAC14 C Tx, C Rx, burst mode
+    add_test(NAME test_OFDM_modem_datac14_ldpc_burst
+             COMMAND sh -c "cd ${CMAKE_CURRENT_BINARY_DIR}/src;
+                            ./ofdm_mod --mode datac14 --in /dev/zero --testframes 1 --verbose 1 --ldpc --bursts 10 |
+                            ./ch - - --No -17 |
+                            ./ofdm_demod --mode datac14 --out /dev/null --testframes --ldpc --verbose 2 --packetsperburst 1")
+
+    # -------------------------------------------------------------------------
     #                                LDPC
     # -------------------------------------------------------------------------
 
@@ -1064,6 +1078,12 @@ if (NOT APPLE)
                             ./freedv_data_raw_tx --testframes 10 DATAC13 /dev/zero /dev/null")
              set_tests_properties(test_memory_leak_FreeDV_DATAC13_tx PROPERTIES PASS_REGULAR_EXPRESSION "ERROR SUMMARY: 0 errors")
 
+     add_test(NAME test_memory_leak_FreeDV_DATAC14_tx
+             COMMAND sh -c "cd  ${CMAKE_CURRENT_BINARY_DIR}/src;
+                            valgrind --leak-check=full --show-leak-kinds=all --track-origins=yes \
+                            ./freedv_data_raw_tx --testframes 10 DATAC14 /dev/zero /dev/null")
+             set_tests_properties(test_memory_leak_FreeDV_DATAC14_tx PROPERTIES PASS_REGULAR_EXPRESSION "ERROR SUMMARY: 0 errors")
+           
      add_test(NAME test_memory_leak_FreeDV_700E_tx
              COMMAND sh -c "cd  ${CMAKE_CURRENT_BINARY_DIR}/src;
                             valgrind --leak-check=full --show-leak-kinds=all --track-origins=yes \
@@ -1307,6 +1327,13 @@ endif(NOT APPLE)
                             ./freedv_data_raw_rx DATAC13 - binaryOut.bin -v;
                             diff binaryIn.bin binaryOut.bin")
 
+     add_test(NAME test_freedv_data_raw_ofdm_datac14_burst_file
+             COMMAND sh -c "cd ${CMAKE_CURRENT_BINARY_DIR}/src;
+                            head -c $((3*10)) </dev/urandom > binaryIn.bin;
+                            ./freedv_data_raw_tx DATAC14 binaryIn.bin - --bursts 10 |
+                            ./freedv_data_raw_rx DATAC14 - binaryOut.bin -v;
+                            diff binaryIn.bin binaryOut.bin")
+
      # FSK LDPC default 100 bit/s 2FSK, enough noise for several % raw BER to give
      # FEC/acquisition a work out, bursts of 1 frame as that stresses acquisition
      add_test(NAME test_freedv_data_raw_fsk_ldpc_100
@@ -1392,6 +1419,7 @@ endif(NOT APPLE)
         test_OFDM_modem_datac3_octave
         test_OFDM_modem_datac4_octave
         test_OFDM_modem_datac13_octave
+        test_OFDM_modem_datac14_octave
         test_fsk_lib_4fsk_ldpc
         test_OFDM_modem_datac0_compression
         PROPERTIES
diff --git a/README.md b/README.md
index 7af0864..a41b034 100644
--- a/README.md
+++ b/README.md
@@ -30,7 +30,7 @@ If you have a Feature Request, please answer the questions in the [Feature Reque
 Before writing any code or submitting a PR - **please discuss** the PR with developers by raising a GitHub Issue. We have many years of experience and a carefully considered plan for Codec 2 development, and can guide you on work that will most benefit this project.
 
 Some key guidelines about the code in the `codec2` repo:
-1. Code that is required to build libcodec2, or to test libcodec2 goes in codec2.
+1. Only code that is required to build, test, or document libcodec2 goes in codec2.
 2. Experimental work, code used for algorithm development, should probably go into some other repo.
 3. Only widely used “production” code goes in codec2. If it has an user base of < 2 (e.g. personal projects, early R&D) - it should probably be application code or a fork.
 
diff --git a/README_data.md b/README_data.md
index 17481f3..49fb9e3 100644
--- a/README_data.md
+++ b/README_data.md
@@ -146,6 +146,7 @@ These modes use an OFDM modem with powerful LDPC codes and are designed for send
 | DATAC3 | 500 | 321 | 126 | (2048,1024) | 3.19 | 74/100 at 0dB | Forward link data (low SNR) |
 | DATAC4 | 250 | 87 | 56 | (1472,448) | 5.17 | 90/100 at -4dB | Forward link data (low SNR) |
 | DATAC13 | 200 | 64 | 14 | (384,128) | 2.0 | 90/100 at -4dB | Reverse link ACK packets (low SNR) |
+| DATAC14 | 250 | 58 | 3 | (112,56) | 0.69 | 90/100 at -2dB | Reverse link ACK packets (low SNR) |
 
 Notes:
 1. 16 bits (2 bytes) per frame are reserved for a 16 bit CRC, e.g. for `datac3` we have 128 byte frames, and 128-2=126 bytes/frame of payload data.
@@ -245,7 +246,7 @@ This command line demonstrates the effect:
 ```
 Try adjusting `--clip` and `No` argument of `ch` (noise level) for different modes.  Note the SNR estimates returned from `freedv_data_raw_rx` compared to the SNR from the channel simulator `ch`. You will notice clipping also increases the RMS power and reduces the PER for a given channel noise power.  CPAPR will also reduce with clipping enabled.
 
-The following plots illustrate the SNR estimates versus actual channel SNR with and without compression (clipping).  Not that even with the uncompressed waveform there is a small offset of around 1dB, possibly due to modem implementation loss or noise in the frequency, phase, or timing estimators.
+The following plots illustrate the SNR estimates versus actual channel SNR with and without compression (clipping).  Note that even with the uncompressed waveform there is a small offset of around 1dB, possibly due to modem implementation loss or noise in the frequency, phase, or timing estimators.
 
 ![](doc/snrest_snr_ctx.png)
 ![](doc/snrest_snr_ctxc.png)
diff --git a/doc/c_tx_comp.png b/doc/c_tx_comp.png
index 5d781c0..a950479 100644
--- a/doc/c_tx_comp.png
+++ b/doc/c_tx_comp.png
diff --git a/doc/c_tx_comp_thruput.png b/doc/c_tx_comp_thruput.png
index 0288f7a..f4010ca 100644
--- a/doc/c_tx_comp_thruput.png
+++ b/doc/c_tx_comp_thruput.png
diff --git a/doc/modem_codec_frame_design.ods b/doc/modem_codec_frame_design.ods
index e6cf1c7..040ba01 100644
--- a/doc/modem_codec_frame_design.ods
+++ b/doc/modem_codec_frame_design.ods
diff --git a/octave/ofdm_helper.m b/octave/ofdm_helper.m
index b34ec23..38c0248 100644
--- a/octave/ofdm_helper.m
+++ b/octave/ofdm_helper.m
@@ -44,7 +44,8 @@ function print_config(states)
   printf("Nc=%d Ts=%4.3f Tcp=%4.3f Ns: %d Np: %d\n", Nc, 1/Rs, Tcp, Ns, Np);
   printf("Nsymperframe: %d Nbitsperpacket: %d Nsamperframe: %d Ntxtbits: %d Nuwbits: %d Nuwframes: %d\n",
           Ns*Nc, Nbitsperpacket, Nsamperframe, Ntxtbits, Nuwbits, Nuwframes);
-  printf("uncoded bits/s: %4.1f\n",  Nbitsperpacket*Fs/(Np*Nsamperframe));
+  printf("uncoded bits/s: %4.1f  Duration (incl post/preamble): %4.2f s\n",
+         Nbitsperpacket*Fs/(Np*Nsamperframe), (Np+2)*Ns*(Tcp+1/Rs));
 end
 
 %-----------------------------------------------------------------------
diff --git a/octave/ofdm_lib.m b/octave/ofdm_lib.m
index 2d3a16e..e4ae35a 100644
--- a/octave/ofdm_lib.m
+++ b/octave/ofdm_lib.m
@@ -1254,7 +1254,7 @@ endfunction
 % with acquisition
 function [rx delay_samples] = ofdm_rx_filter(states, mode, rx)
   delay_samples = 0;
-  if strcmp(mode,"datac4") || strcmp(mode,"datac13")
+  if strcmp(mode,"datac4") || strcmp(mode,"datac13") || strcmp(mode,"datac14")
     w_centre = mean(states.w); centre_norm = w_centre/(2*pi);
     n_coeffs = 100;
     cutoff_Hz = 400; cutoff_norm = cutoff_Hz/states.Fs;
diff --git a/octave/ofdm_mode.m b/octave/ofdm_mode.m
index 074fd84..d88f960 100644
--- a/octave/ofdm_mode.m
+++ b/octave/ofdm_mode.m
@@ -134,6 +134,18 @@ function config = ofdm_init_mode(mode="700D")
     config.state_machine = "data"; 
     config.amp_scale = 2.5*300E3; config.clip_gain1 = 1.2; config.clip_gain2 = 1.0;
     config.txbpf_width_Hz = 400;
+ elseif strcmp(mode,"datac14")
+    Ns=5; config.Np=4; Tcp = 0.005; Ts = 0.018; Nc = 4; config.data_mode = "streaming";
+    config.edge_pilots = 0;
+    config.Ntxtbits = 0; config.Nuwbits = 32; config.bad_uw_errors = 12;
+    config.ftwindow_width = 80; config.timing_mx_thresh = 0.45;
+    config.tx_uw = zeros(1,config.Nuwbits);
+    config.tx_uw(1:24) = [1 1 0 0  1 0 1 0  1 1 1 1  0 0 0 0  1 1 1 1  0 0 0 0];
+    config.tx_uw(end-24+1:end) = [1 1 0 0  1 0 1 0  1 1 1 1  0 0 0 0  1 1 1 1  0 0 0 0];
+    config.amp_est_mode = 1; config.EsNodB = 3;
+    config.state_machine = "data"; 
+    config.amp_scale = 2*300E3; config.clip_gain1 = 2; config.clip_gain2 = 1;
+    config.txbpf_width_Hz = 400;
   elseif strcmp(mode,"1")
     Ns=5; config.Np=10; Tcp=0; Tframe = 0.1; Ts = Tframe/Ns; Nc = 1;
   else
@@ -231,9 +243,17 @@ function [code_param Nbitspercodecframe Ncodecframespermodemframe] = codec_to_fr
     code_param.coded_bits_per_frame = code_param.data_bits_per_frame + code_param.ldpc_parity_bits_per_frame;
     code_param.coded_syms_per_frame = code_param.coded_bits_per_frame/code_param.bits_per_symbol;
   end
+  if strcmp(mode, "datac14")
+    load HRA_56_56.txt
+    code_param = ldpc_init_user(HRA_56_56, modulation, mod_order, mapping);
+    code_param.data_bits_per_frame = 40;
+    code_param.coded_bits_per_frame = code_param.data_bits_per_frame + code_param.ldpc_parity_bits_per_frame;
+    code_param.coded_syms_per_frame = code_param.coded_bits_per_frame/code_param.bits_per_symbol;
+  end
   if strcmp(mode, "datac0") || strcmp(mode, "datac1") || strcmp(mode, "datac3") ...
      || strcmp(mode, "datac4") || strcmp(mode, "qam16c1") ...
-     || strcmp(mode, "qam16c2") || strcmp(mode, "datac5") || strcmp(mode, "datac13")
+     || strcmp(mode, "qam16c2") || strcmp(mode, "datac5") || strcmp(mode, "datac13") ...
+     || strcmp(mode, "datac14")
     printf("ldpc_data_bits_per_frame = %d\n", code_param.ldpc_data_bits_per_frame);
     printf("ldpc_coded_bits_per_frame  = %d\n", code_param.ldpc_coded_bits_per_frame);
     printf("ldpc_parity_bits_per_frame  = %d\n", code_param.ldpc_parity_bits_per_frame);
diff --git a/octave/ofdm_rx.m b/octave/ofdm_rx.m
index fea4b33..6dbe8f6 100644
--- a/octave/ofdm_rx.m
+++ b/octave/ofdm_rx.m
@@ -83,7 +83,9 @@ function ofdm_rx(filename, mode="700D", varargin)
   Nerrs = 0; rx_uw = zeros(1,states.Nuwbits);
 
   % main loop ----------------------------------------------------------------
-  
+
+  rx = ofdm_rx_filter(states, mode, rx);
+
   f = 1;
   while(prx < Nsam)
     
diff --git a/octave/snr_curves_plot.m b/octave/snr_curves_plot.m
new file mode 100644
index 0000000..8baafe0
--- /dev/null
+++ b/octave/snr_curves_plot.m
@@ -0,0 +1,267 @@
+% snr_curves_plot.m
+%
+% Companion script for unittest/raw_data_curves
+
+1;
+
+function state_vec = set_graphics_state_print()
+  textfontsize = get(0,"defaulttextfontsize");
+  linewidth = get(0,"defaultlinelinewidth");
+  markersize = get(0, "defaultlinemarkersize");
+  set(0, "defaulttextfontsize", 16);
+  set(0, "defaultaxesfontsize", 16);
+  set(0, "defaultlinelinewidth", 1);
+  state_vec = [textfontsize linewidth markersize];
+endfunction
+
+function set_graphics_state_screen(state_vec) 
+  textfontsize = state_vec(1);
+  linewidth = state_vec(2);
+  markersize = state_vec(3);
+  set(0, "defaulttextfontsize", textfontsize);
+  set(0, "defaultaxesfontsize", textfontsize);
+  set(0, "defaultlinelinewidth", linewidth);  
+  set(0, "defaultlinemarkersize", markersize);
+endfunction
+
+function [snr_ch per] = snr_scatter(source, mode, channel, colour)
+  suffix = sprintf("_%s_%s_%s",source, mode, channel);
+  snr = load(sprintf("snr%s.txt",suffix));
+  offset = load(sprintf("offset%s.txt",suffix));
+  snr -= offset;
+  snr_x = []; snrest_y = [];
+  for i=1:length(snr)
+    fn = sprintf('snrest%s_%d.txt',suffix,i);
+    if exist(fn,'file') == 2
+      snrest=load(fn);
+      if i == length(snr)
+        plot(snr(i)*ones(1,length(snrest)), snrest, sprintf('%s;%s %s;',colour,source,mode));
+      else
+        plot(snr(i)*ones(1,length(snrest)), snrest, sprintf('%s',colour));
+      end
+      snr_x = [snr_x snr(i)]; snrest_y = [snrest_y mean(snrest)];
+    end
+  end
+  plot(snr_x, snrest_y, sprintf('%s', colour));
+endfunction
+
+function [snr_ch per] = per_snr(mode, colour)
+  snrch = load(sprintf("snrch_%s.txt",mode));
+  snroffset = load(sprintf("snroffset_%s.txt",mode));
+  snrch -= snroffset; 
+  per = load(sprintf("per_%s.txt",mode));
+  plot(snrch, per, sprintf('%so-;%s;', colour, mode));
+endfunction
+
+function snrest_snr_screen(source, channel)
+  clf; hold on;
+  snr_scatter(source, 'datac0', channel,'b+-')
+  snr_scatter(source, 'datac1', channel,'g+-')
+  snr_scatter(source, 'datac3', channel,'r+-')
+  snr_scatter(source, 'datac4', channel,'c+-')
+  snr_scatter(source, 'datac13', channel,'m+-')
+  xlabel('SNR (dB)'); ylabel('SNRest (dB)'); grid('minor');
+  axis([-12 12 -12 12]);
+  a = axis;
+  plot([a(1) a(2)],[a(1) a(2)],'bk-');
+  hold off; grid;
+  if strcmp(source,'ctx')
+    title(sprintf('SNR estimate versus SNR (%s) (no compression)', channel));
+  else
+    title(sprintf('SNR estimate versus SNR (%s) (with compression)', channel));
+  end
+  legend('location','northwest');
+endfunction
+
+function snrest_snr_print(source, channel)
+  state_vec = set_graphics_state_print();
+  snrest_snr_screen(source, channel);
+  print(sprintf("snrest_snr_%s.png", source), "-dpng", "-S1000,800");
+  set_graphics_state_screen(state_vec);
+endfunction
+
+function ber_per_v_snr(source, mode, channel, colour)
+  suffix = sprintf("_%s_%s_%s.txt",source, mode, channel);
+  snr = load(sprintf("snr%s",suffix));
+  offset = load(sprintf("offset%s",suffix));
+  snr -= offset;
+  ber = load(sprintf("ber%s",suffix)) + 1E-6;
+  per = load(sprintf("per%s",suffix)) + 1E-6;
+  semilogy(snr, ber, sprintf('%s;%s %s ber;', colour, source, mode));
+  semilogy(snr, per, sprintf('%s;%s %s per;', colour, source, mode),'linewidth',3,'markersize',10);
+endfunction
+
+function per_v_snr(source, mode, channel, colour)
+  suffix = sprintf("_%s_%s_%s.txt",source, mode, channel);
+  snr = load(sprintf("snr%s",suffix));
+  offset = load(sprintf("offset%s",suffix));
+  snr -= offset;
+  per = load(sprintf("per%s",suffix)) + 1E-6;
+  if strcmp(channel,"awgn")
+    semilogy(snr, per, sprintf('%s;%s %s;', colour, mode, channel));
+  else
+    semilogy(snr, per, sprintf('%s;%s %s;', colour, mode, channel),'linewidth',3,'markersize',10);
+  end
+endfunction
+
+function thruput_v_snr(source, mode, channel, colour)
+  suffix = sprintf("_%s_%s_%s.txt",source, mode, channel);
+  snr = load(sprintf("snr%s",suffix));
+  offset = load(sprintf("offset%s",suffix));
+  snr -= offset;
+  per = load(sprintf("per%s",suffix)) + 1E-6;
+  if strcmp(mode,"datac0") Rb=291; end;
+  if strcmp(mode,"datac1") Rb=980; end;
+  if strcmp(mode,"datac3") Rb=321; end;
+  if strcmp(mode,"datac4") Rb=87; end;
+  if strcmp(mode,"datac13") Rb=65; end;
+  if strcmp(mode,"datac14") Rb=58; end;
+  if strcmp(channel,"awgn")
+    plot(snr, Rb*(1-per), sprintf('%s;%s %s;', colour, mode, channel));
+  else
+    plot(snr, Rb*(1-per), sprintf('%s;%s %s;', colour, mode, channel),'linewidth',3,'markersize',10);
+  end
+endfunction
+
+function octave_ch_noise_screen(channel)
+  clf; hold on;
+  ber_per_v_snr('oct','datac0',channel,'bo-')
+  ber_per_v_snr('ch' ,'datac0',channel,'bx-')
+  ber_per_v_snr('oct','datac1',channel,'go-')
+  ber_per_v_snr('ch' ,'datac1',channel,'gx-')
+  ber_per_v_snr('oct','datac3',channel,'ro-')
+  ber_per_v_snr('ch' ,'datac3',channel,'rx-')
+  xlabel('SNR (dB)'); grid;
+  hold off;
+  if strcmp(channel,"awgn")
+    axis([-6 8 1E-3 1]);
+  else
+    axis([-2 12 1E-3 1]);
+  end
+  title(sprintf('Comparsion of Measuring SNR from Octave and ch tool (%s)', channel));
+endfunction
+
+function octave_ch_noise_print(channel)
+  state_vec = set_graphics_state_print();
+  octave_ch_noise_screen(channel);
+  print(sprintf("octave_ch_noise_%s.png", channel), "-dpng","-S1000,800");
+  set_graphics_state_screen(state_vec);
+endfunction
+
+function octave_c_tx_screen(channel)
+  clf; hold on;
+  ber_per_v_snr('oct','datac0',channel,'bo-')
+  ber_per_v_snr('ctx','datac0',channel,'bx-')
+  ber_per_v_snr('oct','datac1',channel,'go-')
+  ber_per_v_snr('ctx','datac1',channel,'gx-')
+  ber_per_v_snr('oct','datac3',channel,'ro-')
+  ber_per_v_snr('ctx','datac3',channel,'rx-')
+  xlabel('SNR (dB)'); grid;
+  hold off;
+  if strcmp(channel,"awgn")
+    axis([-6 8 1E-3 1]);
+  else
+    axis([-2 12 1E-3 1]);
+  end
+  title(sprintf('Comparsion of Octave Tx and C Tx (no compression) (%s)', channel));
+endfunction
+
+function octave_c_tx_print(channel)
+  state_vec = set_graphics_state_print();
+  octave_c_tx_screen(channel);
+  print(sprintf("octave_c_tx_%s.png", channel), "-dpng","-S1000,800");
+  set_graphics_state_screen(state_vec);
+endfunction
+
+function octave_c_tx_comp_screen(channel)
+  clf; hold on;
+  ber_per_v_snr('oct','datac0',channel,'bo-')
+  ber_per_v_snr('ctxc','datac0',channel,'bx-')
+  ber_per_v_snr('oct','datac1',channel,'go-')
+  ber_per_v_snr('ctxc','datac1',channel,'gx-')
+  ber_per_v_snr('oct','datac3',channel,'ro-')
+  ber_per_v_snr('ctxc','datac3',channel,'rx-')
+  xlabel('SNR (dB)'); grid;
+  hold off;
+  if strcmp(channel,"awgn")
+    axis([-6 8 1E-3 1]);
+  else
+    axis([-2 12 1E-3 1]);
+  end
+  title(sprintf('Comparsion of Octave Tx and C Tx (with compression) (%s)', channel));
+endfunction
+
+function octave_c_tx_comp_print(channel)
+  state_vec = set_graphics_state_print();
+  octave_c_tx_comp_screen(channel);
+  print(sprintf("octave_c_tx_comp_%s.png", channel), "-dpng","-S1000,800");
+  set_graphics_state_screen(state_vec);
+endfunction
+
+% composite AWGN and MPP for compressed
+function c_tx_comp_screen
+  clf; hold on;
+  per_v_snr('ctxc','datac0','awgn','bo-')
+  per_v_snr('ctxc','datac1','awgn','go-')
+  per_v_snr('ctxc','datac3','awgn','ro-')
+  per_v_snr('ctxc','datac4','awgn','co-')
+  per_v_snr('ctxc','datac13','awgn','mo-')
+  per_v_snr('ctxc','datac14','awgn','ko-')
+  per_v_snr('ctxc','datac0','mpp','bx-')
+  per_v_snr('ctxc','datac1','mpp','gx-')
+  per_v_snr('ctxc','datac3','mpp','rx-')
+  per_v_snr('ctxc','datac4','mpp','cx-')
+  per_v_snr('ctxc','datac13','mpp','mx-')
+  per_v_snr('ctxc','datac14','mpp','kx-')
+  xlabel('SNR (dB)'); ylabel('PER'); grid;
+  hold off;
+  axis([-10 14 1E-3 1]);
+  title('PER of C Raw Data Modes (with compression)');
+endfunction
+
+function c_tx_comp_print;
+  state_vec = set_graphics_state_print();
+  c_tx_comp_screen;
+  print("c_tx_comp.png", "-dpng","-S1000,800");
+  set_graphics_state_screen(state_vec);
+endfunction
+
+function c_tx_comp_thruput_screen
+  clf; hold on;
+  thruput_v_snr('ctxc','datac0','awgn','bo-')
+  thruput_v_snr('ctxc','datac1','awgn','go-')
+  thruput_v_snr('ctxc','datac3','awgn','ro-')
+  thruput_v_snr('ctxc','datac4','awgn','co-')
+  thruput_v_snr('ctxc','datac13','awgn','mo-')
+  thruput_v_snr('ctxc','datac14','awgn','ko-')
+  thruput_v_snr('ctxc','datac0','mpp','bx-')
+  thruput_v_snr('ctxc','datac1','mpp','gx-')
+  thruput_v_snr('ctxc','datac3','mpp','rx-')
+  thruput_v_snr('ctxc','datac4','mpp','cx-')
+  thruput_v_snr('ctxc','datac13','mpp','mx-')
+  thruput_v_snr('ctxc','datac14','mpp','kx-')
+  xlabel('SNR (dB)'); ylabel('bits/s'); grid;
+  hold off;
+  axis([-10 10 0 1000]);
+  title(' Throughput for C Tx (with compression)');
+  legend('location','west');
+endfunction
+
+function c_tx_comp_thruput_print;
+  state_vec = set_graphics_state_print;
+  c_tx_comp_thruput_screen;
+  print("c_tx_comp_thruput.png", "-dpng","-S1000,800");
+  set_graphics_state_screen(state_vec);
+endfunction
+
+#{
+figure(1); octave_ch_noise_screen;
+figure(2); octave_c_tx_screen;
+figure(3); octave_c_tx_comp_screen
+figure(4); snrest_snr_screen;
+
+figure(5); octave_ch_noise_print;
+figure(6); octave_c_tx_print;
+figure(7); octave_c_tx_comp_print;
+figure(8); snrest_snr_print;
+#}
diff --git a/src/ch.c b/src/ch.c
index 9d8d895..45e1b49 100644
--- a/src/ch.c
+++ b/src/ch.c
@@ -256,7 +256,7 @@ int main(int argc, char *argv[]) {
             stderr,
             "\nAdjust path --fading_dir or use GNU Octave to generate:\n\n");
       gen_fading_file:
-        fprintf(stderr, "$ octave --no-gui\n");
+        fprintf(stderr, "$ octave-cli\n");
         fprintf(stderr, "octave:24> pkg load signal\n");
         fprintf(stderr, "octave:24> time_secs=60\n");
         fprintf(stderr,
diff --git a/src/freedv_700.c b/src/freedv_700.c
index 3dc4329..7c8536c 100644
--- a/src/freedv_700.c
+++ b/src/freedv_700.c
@@ -197,6 +197,7 @@ void freedv_ofdm_data_open(struct freedv *f) {
   if (f->mode == FREEDV_MODE_DATAC3) strcpy(mode, "datac3");
   if (f->mode == FREEDV_MODE_DATAC4) strcpy(mode, "datac4");
   if (f->mode == FREEDV_MODE_DATAC13) strcpy(mode, "datac13");
+  if (f->mode == FREEDV_MODE_DATAC14) strcpy(mode, "datac14");
 
   ofdm_init_mode(mode, &ofdm_config);
   f->ofdm = ofdm_create(&ofdm_config);
diff --git a/src/freedv_api.c b/src/freedv_api.c
index 5172959..3ccf63d 100644
--- a/src/freedv_api.c
+++ b/src/freedv_api.c
@@ -125,7 +125,8 @@ struct freedv *freedv_open_advanced(int mode, struct freedv_advanced *adv) {
        FDV_MODE_ACTIVE(FREEDV_MODE_DATAC1, mode) ||
        FDV_MODE_ACTIVE(FREEDV_MODE_DATAC3, mode) ||
        FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, mode) ||
-       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, mode)) == false)
+       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, mode) ||
+       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, mode)) == false)
     return NULL;
 
   /* set everything to zero just in case */
@@ -154,6 +155,7 @@ struct freedv *freedv_open_advanced(int mode, struct freedv_advanced *adv) {
   if (FDV_MODE_ACTIVE(FREEDV_MODE_DATAC3, mode)) freedv_ofdm_data_open(f);
   if (FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, mode)) freedv_ofdm_data_open(f);
   if (FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, mode)) freedv_ofdm_data_open(f);
+  if (FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, mode)) freedv_ofdm_data_open(f);
 
   varicode_decode_init(&f->varicode_dec_states, 1);
 
@@ -235,7 +237,8 @@ void freedv_close(struct freedv *freedv) {
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC1, freedv->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC3, freedv->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, freedv->mode) ||
-      FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, freedv->mode)) {
+      FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, freedv->mode) ||
+      FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, freedv->mode)) {
     FREE(freedv->rx_syms);
     FREE(freedv->rx_amps);
     FREE(freedv->ldpc);
@@ -266,7 +269,8 @@ static int is_ofdm_mode(struct freedv *f) {
          FDV_MODE_ACTIVE(FREEDV_MODE_DATAC1, f->mode) ||
          FDV_MODE_ACTIVE(FREEDV_MODE_DATAC3, f->mode) ||
          FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, f->mode) ||
-         FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, f->mode);
+         FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, f->mode) ||
+         FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, f->mode);
 }
 
 static int is_ofdm_data_mode(struct freedv *f) {
@@ -274,7 +278,8 @@ static int is_ofdm_data_mode(struct freedv *f) {
          FDV_MODE_ACTIVE(FREEDV_MODE_DATAC1, f->mode) ||
          FDV_MODE_ACTIVE(FREEDV_MODE_DATAC3, f->mode) ||
          FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, f->mode) ||
-         FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, f->mode);
+         FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, f->mode) ||
+         FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, f->mode);
 }
 
 /*---------------------------------------------------------------------------*\
@@ -464,7 +469,8 @@ void freedv_rawdatacomptx(struct freedv *f, COMP mod_out[],
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC1, f->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC3, f->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, f->mode) ||
-      FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, f->mode))
+      FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, f->mode) ||
+      FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, f->mode))
     freedv_comptx_ofdm(f, mod_out);
 
   if (FDV_MODE_ACTIVE(FREEDV_MODE_FSK_LDPC, f->mode)) {
@@ -1063,7 +1069,8 @@ int freedv_rawdatacomprx(struct freedv *f, unsigned char *packed_payload_bits,
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC1, f->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC3, f->mode) ||
       FDV_MODE_ACTIVE(FREEDV_MODE_DATAC4, f->mode) ||
-      FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, f->mode))
+      FDV_MODE_ACTIVE(FREEDV_MODE_DATAC13, f->mode) ||
+      FDV_MODE_ACTIVE(FREEDV_MODE_DATAC14, f->mode))
     rx_status = freedv_comp_short_rx_ofdm(f, (void *)demod_in, 0, 1.0f);
   if (FDV_MODE_ACTIVE(FREEDV_MODE_FSK_LDPC, f->mode)) {
     rx_status = freedv_rx_fsk_ldpc_data(f, demod_in);
diff --git a/src/freedv_api.h b/src/freedv_api.h
index ce95a55..e4ca468 100644
--- a/src/freedv_api.h
+++ b/src/freedv_api.h
@@ -61,6 +61,7 @@ extern "C" {
 #define FREEDV_MODE_DATAC0 14
 #define FREEDV_MODE_DATAC4 18
 #define FREEDV_MODE_DATAC13 19
+#define FREEDV_MODE_DATAC14 20
 
 // Sample rates used
 #define FREEDV_FS_8000 8000
@@ -140,6 +141,9 @@ extern "C" {
 #if !defined(FREEDV_MODE_DATAC13_EN)
 #define FREEDV_MODE_DATAC13_EN FREEDV_MODE_EN_DEFAULT
 #endif
+#if !defined(FREEDV_MODE_DATAC14_EN)
+#define FREEDV_MODE_DATAC14_EN FREEDV_MODE_EN_DEFAULT
+#endif
 
 #define FDV_MODE_ACTIVE(mode_name, var) \
   ((mode_name##_EN) == 0 ? 0 : (var) == mode_name)
diff --git a/src/freedv_data_raw_rx.c b/src/freedv_data_raw_rx.c
index 1957e10..0353ae5 100644
--- a/src/freedv_data_raw_rx.c
+++ b/src/freedv_data_raw_rx.c
@@ -214,6 +214,8 @@ int main(int argc, char *argv[]) {
     mode = FREEDV_MODE_DATAC4;
   if (!strcmp(argv[dx], "DATAC13") || !strcmp(argv[dx], "datac13"))
     mode = FREEDV_MODE_DATAC13;
+  if (!strcmp(argv[dx], "DATAC14") || !strcmp(argv[dx], "datac14"))
+    mode = FREEDV_MODE_DATAC14;
   if (mode == -1) {
     fprintf(stderr, "Error in mode: %s\n", argv[dx]);
     exit(1);
diff --git a/src/freedv_data_raw_tx.c b/src/freedv_data_raw_tx.c
index 44d53e9..cb74107 100644
--- a/src/freedv_data_raw_tx.c
+++ b/src/freedv_data_raw_tx.c
@@ -236,6 +236,8 @@ int main(int argc, char *argv[]) {
     mode = FREEDV_MODE_DATAC4;
   if (!strcmp(argv[dx], "DATAC13") || !strcmp(argv[dx], "datac13"))
     mode = FREEDV_MODE_DATAC13;
+  if (!strcmp(argv[dx], "DATAC14") || !strcmp(argv[dx], "datac14"))
+    mode = FREEDV_MODE_DATAC14;
   if (mode == -1) {
     fprintf(stderr, "Error: in mode: %s", argv[dx]);
     exit(1);
diff --git a/src/gp_interleaver.c b/src/gp_interleaver.c
index 61678f8..6710b0c 100644
--- a/src/gp_interleaver.c
+++ b/src/gp_interleaver.c
@@ -44,6 +44,7 @@
 */
 
 static const int b_table[] = {
+    48,   31,  /* datac14: HRA_56_56, 40 data bits used          */
     56,   37,  /* 700E:   HRA_56_56                              */
     106,  67,  /* 2020B:  (112,56) partial protection            */
     112,  71,  /* 700D:   HRA_112_112                            */
diff --git a/src/interldpc.c b/src/interldpc.c
index 24f4b2a..8cec647 100644
--- a/src/interldpc.c
+++ b/src/interldpc.c
@@ -78,6 +78,7 @@ void ldpc_mode_specific_setup(struct OFDM *ofdm, struct LDPC *ldpc) {
   }
   if (!strcmp(ofdm->mode, "datac4")) set_data_bits_per_frame(ldpc, 448);
   if (!strcmp(ofdm->mode, "datac13")) set_data_bits_per_frame(ldpc, 128);
+  if (!strcmp(ofdm->mode, "datac14")) set_data_bits_per_frame(ldpc, 40);
 }
 
 /* LDPC encode frame - generate parity bits and a codeword, applying the
diff --git a/src/ofdm.c b/src/ofdm.c
index 28d6dba..ba22f3f 100644
--- a/src/ofdm.c
+++ b/src/ofdm.c
@@ -559,7 +559,8 @@ static void allocate_tx_bpf(struct OFDM *ofdm) {
     quisk_filt_cfInit(ofdm->tx_bpf, filtP400S600,
                       sizeof(filtP400S600) / sizeof(float));
     quisk_cfTune(ofdm->tx_bpf, ofdm->tx_centre / ofdm->fs);
-  } else if (!strcmp(ofdm->mode, "datac4") || !strcmp(ofdm->mode, "datac13")) {
+  } else if (!strcmp(ofdm->mode, "datac4") || !strcmp(ofdm->mode, "datac13") ||
+             !strcmp(ofdm->mode, "datac14")) {
     quisk_filt_cfInit(ofdm->tx_bpf, filtP200S400,
                       sizeof(filtP200S400) / sizeof(float));
     // centre the filter on the mean carrier freq, allows a narrower filter to
@@ -590,7 +591,8 @@ static void allocate_rx_bpf(struct OFDM *ofdm) {
 
   /* Receive bandpass filter; complex coefficients, center frequency */
 
-  if (!strcmp(ofdm->mode, "datac4") || !strcmp(ofdm->mode, "datac13")) {
+  if (!strcmp(ofdm->mode, "datac4") || !strcmp(ofdm->mode, "datac13") ||
+      !strcmp(ofdm->mode, "datac14")) {
     quisk_filt_cfInit(ofdm->rx_bpf, filtP200S400,
                       sizeof(filtP200S400) / sizeof(float));
     // centre the filter on the mean carrier freq, allows a narrower filter to
diff --git a/src/ofdm_mode.c b/src/ofdm_mode.c
index 1aabb1a..df0b4f5 100644
--- a/src/ofdm_mode.c
+++ b/src/ofdm_mode.c
@@ -226,6 +226,31 @@ void ofdm_init_mode(char mode[], struct OFDM_CONFIG *config) {
     config->clip_gain1 = 1.2;
     config->clip_gain2 = 1.0;
     config->rx_bpf_en = true;
+  } else if (strcmp(mode, "datac14") == 0) {
+    config->ns = 5;
+    config->np = 4;
+    config->tcp = 0.005;
+    config->ts = 0.018;
+    config->nc = 4;
+    config->edge_pilots = 0;
+    config->txtbits = 0;
+    config->state_machine = "data";
+    config->ftwindowwidth = 80;
+    config->timing_mx_thresh = 0.45;
+    config->codename = "HRA_56_56";
+    config->amp_est_mode = 1;
+    config->nuwbits = 32;
+    config->bad_uw_errors = 12;
+    uint8_t uw[] = {1, 1, 0, 0, 1, 0, 1, 0, 1, 1, 1, 1,
+                    0, 0, 0, 0, 1, 1, 1, 1, 0, 0, 0, 0};
+    assert(sizeof(uw) <= MAX_UW_BITS);
+    memcpy(config->tx_uw, uw, sizeof(uw));
+    memcpy(&config->tx_uw[config->nuwbits - sizeof(uw)], uw, sizeof(uw));
+    config->data_mode = "streaming";
+    config->amp_scale = 2.0 * 300E3;
+    config->clip_gain1 = 2.0;
+    config->clip_gain2 = 1.0;
+    config->rx_bpf_en = true;
   } else {
     assert(0);
   }
diff --git a/unittest/check_peak.sh b/unittest/check_peak.sh
index 8f41c2a..b357534 100755
--- a/unittest/check_peak.sh
+++ b/unittest/check_peak.sh
@@ -51,6 +51,7 @@ if [ "$1" == "LPCNet" ]; then
     data_test "datac3"
     data_test "datac4"
     data_test "datac13"
+    data_test "datac14"
 fi
 
 exit 0
diff --git a/unittest/raw_data_curves/Makefile b/unittest/raw_data_curves/Makefile
new file mode 100644
index 0000000..09aa7ca
--- /dev/null
+++ b/unittest/raw_data_curves/Makefile
@@ -0,0 +1,149 @@
+# Makefile
+# Dec 2022
+#
+# Automates PER/BER curve generation for raw data mode:
+#
+# 1. Compare "ch" noise injection/SNR measurement against reference Octave Tx
+# 2. Compare C Tx against Octave Tx (with and without compression)
+# 3. Plot curves for SNR estimated from C Rx against actual SNR
+# 4. Plot AWGN/PER C Tx curves for end user documentation
+#
+# usage:
+#
+# 1. Create 20 minutes of MPP fading samples:
+#    $ cd codec2/octave/
+#    $ octave-cli
+#    octave:24> pkg load signal
+#    octave:24> time_secs=60*20
+#    octave:26> ch_fading("~/codec2/build_linux/unittest/fast_fading_samples.float", 8000, 1.0, 8000*time_secs)
+#
+# 2. Run scripts:
+#
+#    $ make
+
+SHELL  := /bin/bash
+CODEC2 := $(HOME)/codec2
+
+all: test \
+     octave_ch_noise_awgn.png octave_c_tx_awgn.png octave_c_tx_comp_awgn.png \
+     octave_ch_noise_mpp.png octave_c_tx_mpp.png octave_c_tx_comp_mpp.png \
+     snrest_snr_ctx.png snrest_snr_ctxc.png \
+     c_tx_comp.png c_tx_comp_thruput.png
+
+clean:
+	rm -f *.txt *.png *.raw
+
+# run this first, traps common CML setup error
+test:
+	source snr_curves.sh; test_ldpc
+
+# subset of files generated, but enough to set up Makefile dependencies
+snr_oct =  snr_oct_datac0_awgn.txt  snr_oct_datac1_awgn.txt  snr_oct_datac3_awgn.txt
+snr_ch  =  snr_ch_datac0_awgn.txt   snr_ch_datac1_awgn.txt   snr_ch_datac3_awgn.txt
+snr_ctx =  snr_ctx_datac0_awgn.txt  snr_ctx_datac1_awgn.txt  snr_ctx_datac3_awgn.txt
+snr_ctxc = snr_ctxc_datac0_awgn.txt snr_ctxc_datac3_awgn.txt
+
+snr_oct_mpp  = snr_oct_datac0_mpp.txt  snr_oct_datac1_mpp.txt  snr_oct_datac3_mpp.txt
+snr_ch_mpp   = snr_ch_datac0_mpp.txt   snr_ch_datac1_mpp.txt   snr_ch_datac3_mpp.txt
+snr_ctx_mpp  = snr_ctx_datac0_mpp.txt  snr_ctx_datac1_mpp.txt  snr_ctx_datac3_mpp.txt
+snr_ctxc_mpp = snr_ctxc_datac0_mpp.txt snr_ctxc_datac3_mpp.txt
+
+$(snr_oct):
+	source snr_curves.sh; generate_octave_tx_data datac0 awgn
+	source snr_curves.sh; generate_octave_tx_data datac1 awgn
+	source snr_curves.sh; generate_octave_tx_data datac3 awgn
+
+$(snr_oct_mpp):
+	source snr_curves.sh; generate_octave_tx_data datac0 mpp
+	source snr_curves.sh; generate_octave_tx_data datac1 mpp
+	source snr_curves.sh; generate_octave_tx_data datac3 mpp
+
+$(snr_ch):
+	source snr_curves.sh; generate_ch_data datac0 awgn
+	source snr_curves.sh; generate_ch_data datac1 awgn
+	source snr_curves.sh; generate_ch_data datac3 awgn
+
+$(snr_ch_mpp):
+	source snr_curves.sh; generate_ch_data datac0 mpp
+	source snr_curves.sh; generate_ch_data datac1 mpp
+	source snr_curves.sh; generate_ch_data datac3 mpp
+
+# C without compression
+
+$(snr_ctx):
+	source snr_curves.sh; generate_snrest_v_snr_data datac0 awgn
+	source snr_curves.sh; generate_snrest_v_snr_data datac1 awgn
+	source snr_curves.sh; generate_snrest_v_snr_data datac3 awgn
+	source snr_curves.sh; generate_snrest_v_snr_data datac4 awgn
+	source snr_curves.sh; generate_snrest_v_snr_data datac13 awgn
+	source snr_curves.sh; generate_snrest_v_snr_data datac14 awgn
+
+$(snr_ctx_mpp):
+	source snr_curves.sh; generate_snrest_v_snr_data datac0 mpp
+	source snr_curves.sh; generate_snrest_v_snr_data datac1 mpp
+	source snr_curves.sh; generate_snrest_v_snr_data datac3 mpp
+	source snr_curves.sh; generate_snrest_v_snr_data datac4 mpp
+	source snr_curves.sh; generate_snrest_v_snr_data datac13 mpp
+	source snr_curves.sh; generate_snrest_v_snr_data datac14 mpp
+
+# C with compression
+
+$(snr_ctxc):
+	source snr_curves.sh; generate_snrest_v_snr_data datac0 awgn 1
+	source snr_curves.sh; generate_snrest_v_snr_data datac1 awgn 1
+	source snr_curves.sh; generate_snrest_v_snr_data datac3 awgn 1
+	source snr_curves.sh; generate_snrest_v_snr_data datac4 awgn 1
+	source snr_curves.sh; generate_snrest_v_snr_data datac13 awgn 1
+	source snr_curves.sh; generate_snrest_v_snr_data datac14 awgn 1
+
+$(snr_ctxc_mpp):
+	source snr_curves.sh; generate_snrest_v_snr_data datac0 mpp 1
+	source snr_curves.sh; generate_snrest_v_snr_data datac1 mpp 1
+	source snr_curves.sh; generate_snrest_v_snr_data datac3 mpp 1
+	source snr_curves.sh; generate_snrest_v_snr_data datac4 mpp 1
+	source snr_curves.sh; generate_snrest_v_snr_data datac13 mpp 1
+	source snr_curves.sh; generate_snrest_v_snr_data datac14 mpp 1
+
+# Octave and C curves should be on top of each other, indicating Octave
+# and ch noise injection/SNR measurement are equivalent
+octave_ch_noise_awgn.png: $(snr_oct) $(snr_ch)
+	echo "snr_curves_plot; octave_ch_noise_print('awgn'); quit" | \
+        octave-cli -p $(CODEC2)/octave
+octave_ch_noise_mpp.png: $(snr_oct_mpp) $(snr_ch_mpp)
+	echo "snr_curves_plot; octave_ch_noise_print('mpp'); quit" | \
+        octave-cli -p $(CODEC2)/octave
+
+# Octave Tx and C Tx curves should be on top of each other
+octave_c_tx_awgn.png: $(snr_oct) $(snr_ctx)
+	echo "snr_curves_plot; octave_c_tx_print('awgn'); quit" | \
+        octave-cli -p $(CODEC2)/octave
+octave_c_tx_mpp.png: $(snr_oct_mpp) $(snr_ctx_mpp)
+	echo "snr_curves_plot; octave_c_tx_print('mpp'); quit" | \
+        octave-cli -p $(CODEC2)/octave
+
+# Octave Tx and C Tx (compressed) curves should be close, but C may be 1dB
+# poorer
+octave_c_tx_comp_awgn.png: $(snr_oc) $(snr_ctxc)
+	echo "snr_curves_plot; octave_c_tx_comp_print('awgn'); quit" | \
+        octave-cli -p $(CODEC2)/octave
+octave_c_tx_comp_mpp.png: $(snr_oct_mpp) $(snr_ctxc_mpp)
+	echo "snr_curves_plot; octave_c_tx_comp_print('mpp'); quit" | \
+        octave-cli -p $(CODEC2)/octave
+
+# combined AWGN and MPP from C Tx (compressed) - what end users would run
+c_tx_comp.png: $(snr_ctxc) $(snr_ctxc_mpp)
+	echo "snr_curves_plot; c_tx_comp_print; quit" | \
+        octave-cli -p $(CODEC2)/octave
+
+# Curves of SNR estimates from C Rx compared to actual SNR, useful for "gear shifting"
+snrest_snr_ctx.png: $(snr_ctx)
+	echo "snr_curves_plot; snrest_snr_print('ctx', 'awgn'); quit" | \
+        octave-cli -p $(CODEC2)/octave
+snrest_snr_ctxc.png: $(snr_ctxc)
+	echo "snr_curves_plot; snrest_snr_print('ctxc', 'awgn'); quit" | \
+        octave-cli -p $(CODEC2)/octave
+
+# Throughput of payload data in bits/s of modes against SNR
+c_tx_comp_thruput.png: $(snr_ctxc) $(snr_ctxc_mpp)
+	echo "snr_curves_plot; c_tx_comp_thruput_print; quit" | \
+        octave-cli -p $(CODEC2)/octave
diff --git a/unittest/raw_data_curves/snr_curves.sh b/unittest/raw_data_curves/snr_curves.sh
new file mode 100755
index 0000000..62f0a52
--- /dev/null
+++ b/unittest/raw_data_curves/snr_curves.sh
@@ -0,0 +1,191 @@
+# snr_curves.sh
+#
+# Library of bash functions to generate data for SNR curves.
+#
+# testing a function example:
+#   $ bash -c "source ./snr_curves.sh; generate_octave_tx_data datac0 awgn"
+
+set -x
+
+PATH=${PATH}:${HOME}/codec2/build_linux/src
+CODEC2=${HOME}/codec2
+FADING_DIR=${CODEC2}/build_linux/unittest
+
+snr_list='-5 -4 -3 -2 0 1 2 4'
+No_list='-13 -14 -15 -16 -18 -20 -22 -24 -26'
+Nbursts_awgn=20
+Nbursts_mpp=100
+
+# Octave Tx injects noise and is source of truth for SNR, measure BER/PER v SNR
+function generate_octave_tx_data {
+  mode=$1
+  channel=$2
+  
+  Nbursts=$Nbursts_awgn
+  snr_nudge=0
+  if [ "$channel" == "mpp" ]; then
+    Nbursts=$Nbursts_mpp
+    snr_nudge=4  
+  fi
+  
+  rx_log=$(mktemp)
+
+  i=1
+  rm -f snr_oct_${mode}_${channel}*.txt
+  rm -f ber_oct_${mode}_${channel}*.txt
+  rm -f per_oct_${mode}_${channel}*.txt
+  for snr in $snr_list
+  do
+    snr_adj=$((${snr}+${snr_nudge}))  
+    echo "warning ('off', 'Octave:data-file-in-path');
+    ofdm_ldpc_tx('test_${mode}.raw','${mode}',1,${snr_adj},'${channel}','bursts',${Nbursts},'crc');
+    quit" | DISPLAY="" octave-cli -p ${CODEC2}/octave
+    freedv_data_raw_rx --testframes $mode test_${mode}.raw /dev/null 2>${rx_log} -v
+    BERmeas=$(cat ${rx_log} | grep 'BER......:' | cut -d' ' -f2)
+    PERmeas=$(cat ${rx_log} | grep 'Coded FER' | cut -d' ' -f3)
+    
+    echo ${snr_adj} >> snr_oct_${mode}_${channel}.txt
+    echo ${BERmeas} >> ber_oct_${mode}_${channel}.txt
+    echo ${PERmeas} >> per_oct_${mode}_${channel}.txt
+    i=$((i+1))
+  done
+  echo 0 > offset_oct_${mode}_${channel}.txt
+}
+
+# ch injects noise and is source of truth for SNR, measure BER/PER v SNR
+# Octave Tx
+function generate_ch_data {
+  mode=$1
+  channel=$2
+
+  ch_multipath=''
+  Nbursts=$Nbursts_awgn
+  snr_nudge=0  
+  if [ "$channel" == "mpp" ]; then
+    ch_multipath='--mpp'
+    Nbursts=$Nbursts_mpp
+    snr_nudge=4  
+  fi    
+    
+  octave_log=$(mktemp)
+  ch_log=$(mktemp)
+  rx_log=$(mktemp)
+
+  i=1
+  rm -f snr_ch_${mode}_${channel}*.txt
+  rm -f ber_ch_${mode}_${channel}*.txt
+  rm -f per_ch_${mode}_${channel}*.txt
+  for No in $No_list
+  do
+    No_adj=$((${No}-${snr_nudge}))  
+    echo "warning ('off', 'Octave:data-file-in-path');
+    ofdm_ldpc_tx('test_${mode}.raw','${mode}',1,100,'awgn','bursts',${Nbursts},'crc'); 
+    quit" | DISPLAY="" octave-cli -p ${CODEC2}/octave 1>${octave_log}
+    SNRoffset=$(cat ${octave_log} | grep 'Burst offset:' | cut -d' ' -f5)
+    
+    ch test_${mode}.raw - --No $No_adj ${ch_multipath} --fading_dir ${FADING_DIR} 2>>${ch_log} | \
+    freedv_data_raw_rx --testframes $mode - /dev/null -v 2>${rx_log}
+    BERmeas=$(cat ${rx_log} | grep 'BER......:' | cut -d' ' -f2)
+    PERmeas=$(cat ${rx_log} | grep 'Coded FER' | cut -d' ' -f3)
+    
+    echo ${BERmeas} >> ber_ch_${mode}_${channel}.txt
+    echo ${PERmeas} >> per_ch_${mode}_${channel}.txt
+    i=$((i+1))
+
+    # trap not enough fading file samples (with mpp)
+    grep "Fading file finished" ${ch_log}
+    if [ $? -eq 0 ]; then
+        cat ${ch_log}
+        exit 1
+    fi
+  done
+  
+  echo ${SNRoffset} > offset_ch_${mode}_${channel}.txt
+  SNRch=$(cat ${ch_log} | grep SNR3k | tr -s ' ' | cut -d' ' -f3)
+  echo ${SNRch} > snr_ch_${mode}_${channel}.txt
+}
+
+# ch injects noise and is source of truth for SNR, measure BER/PER v SNR and
+# SNR estimates v SNR from rx, C Tx
+function generate_snrest_v_snr_data {
+  mode=$1
+  channel=$2  
+
+  snr_nudge=0
+  aNo_list=$No_list
+
+  # nudge SNR test range to get meaningful results for these tests  
+  if [ "$mode" == "datac1" ]; then
+    snr_nudge=4
+  fi
+  if [[ "$mode" == "datac4" || "$mode" == "datac13" || "$mode" == "datac14" ]]; then
+    snr_nudge=-6
+  fi
+  
+  ch_multipath=''
+  Nbursts=$Nbursts_awgn
+  if [ "$channel" == "mpp" ]; then
+    ch_multipath='--mpp'
+    Nbursts=$Nbursts_mpp
+    snr_nudge=$((${snr_nudge}+4))
+  fi    
+
+  clip=0
+  id='ctx'
+  if [ "$#" -eq 3 ]; then
+    clip=$3
+    id='ctxc'
+    snr_nudge=$((${snr_nudge}-4))
+  fi
+
+  tx_log=$(mktemp)
+  ch_log=$(mktemp)
+  rx_log=$(mktemp)
+
+  i=1
+  rm -f snrest_${id}_${mode}_${channel}*.txt
+  rm -f ber_${id}_${mode}_${channel}*.txt
+  rm -f per_${id}_${mode}_${channel}*.txt
+  for No in $aNo_list
+  do
+    No_adj=$((${No}-${snr_nudge}))  
+    freedv_data_raw_tx --clip ${clip} --delay 1000 --txbpf ${clip} --bursts $Nbursts --testframes $Nbursts $mode /dev/zero - 2>${tx_log} | \
+    ch - - --No $No_adj ${ch_multipath} --fading_dir ${FADING_DIR} 2>>${ch_log} | \
+    freedv_data_raw_rx --testframes $mode - /dev/null 2>${rx_log} -v
+    SNRoffset=$(cat ${tx_log} | grep "mark:space" | tr -s ' ' | cut -d' ' -f 5)
+   
+    SNRest=$(cat ${rx_log} | grep '\-BS\-' | tr -s ' ' | cut -d' ' -f17)
+    if [ ! -z "$SNRest" ]; then
+      echo ${SNRest} > snrest_${id}_${mode}_${channel}_${i}.txt
+    fi
+    BERmeas=$(cat ${rx_log} | grep 'BER......:' | cut -d' ' -f2)
+    PERmeas=$(cat ${rx_log} | grep 'Coded FER' | cut -d' ' -f3)
+    echo ${BERmeas} >> ber_${id}_${mode}_${channel}.txt
+    echo ${PERmeas} >> per_${id}_${mode}_${channel}.txt
+    i=$((i+1))
+  done
+
+  echo ${SNRoffset} > offset_${id}_${mode}_${channel}.txt
+ 
+  # trap not enough fading file samples (with mpp)
+  grep "Fading file finished" ${ch_log}
+  if [ $? -eq 0 ]; then
+      cat ${ch_log}
+      exit 1
+  fi
+  SNRch=$(cat ${ch_log} | grep SNR3k | tr -s ' ' | cut -d' ' -f3)
+  echo ${SNRch} > snr_${id}_${mode}_${channel}.txt
+}
+
+# Sanity check to make sure Octave/CML is set up OK
+function test_ldpc {
+  echo "ldpcut; quit" | DISPLAY="" octave-cli -p ${CODEC2}/octave
+  if [ "$?" -ne 0 ]; then
+    echo "basic octave test failed, you may need to"
+    echo "(a) run ctests to create build_xxx/cml"
+    echo "(b) set up ~/.octaverc as per octave/ldpc.m"
+    exit 1
+  else
+      echo "OK"
+  fi
+}